In the case of such a rear view mirror, disclosed by German published examined patent application 28 22 681 (corresponding to French published patent application 24 26 590 and Swedish published patent application 79 04 338), positioning drives are mounted on a base plate which is rigidly connected to the fixing device. The positioning element of one positioning drive directly engages the housing and pivots the housing about a transverse axis of a universal joint disposed between the housing and the base plate. The other positioning drive engages the universal joint and thus pivots the housing about its longitudinal axis. This prior art mirror is structurally cumbersome so that fitting it is very expensive. Furthermore, the depth of fitment of the servo-motor arrangement is relatively considerable so that the housing in turn becomes so deep that the driver's field of view in an obliquely forward direction is considerably restricted, which is a disadvantage when manoeuvring, where a very precise utilization of space is important.
In order to resolve this last mentioned problem, it is already known from European published patent application 0 090 909 for the servo-motor arrangement of motor-powered adjustable rear view mirrors to be connected directly to the fixing device. This known development does not however result in a sufficiently stable connection between housing and fixing device, particularly in the case of large rear view mirrors.
Known from German published patent application 31 20 627 is a motor-powered adjustable rear view mirror the housing of which is rigidly connected to a fixing device. A sheet of mirror glass connected to a supporting plate is connected to the housing and can be pivoted via a universal joint so that it is therefore pivoted in relation to the housing. Mounted on the housing are two positioning drives which are connected to the mirror glass via crank transmissions. This construction is of considerable depth, since the positioning drives are spatially disposed between the mirror glass and the rear wall of the housing and since furthermore space is required for the crank transmissions. Furthermore, this development is based on an essential prerequisite that the sheet of mirror glass is not rigidly connected to the housing, so that moisture and dirt can penetrate the assembly.